Seven ‘earth-like’ planets discovered

Posted on February 22, 2017 by petrel41

This video says about itself:

NASA & TRAPPIST-1: A Treasure Trove of Planets Found

22 February 2017

Seven Earth-sized planets have been observed by NASA’s Spitzer Space Telescope around a tiny, nearby, ultra-cool dwarf star called TRAPPIST-1. Three of these planets are firmly in the habitable zone.

Over 21 days, NASA’s Spitzer Space Telescope measured the drop in light as each planet passed in front of the star. Spitzer was able to identify a total of seven rocky worlds, including three in the habitable zone, where liquid water might be found.

The video features interviews with Sean Carey, manager of the Spitzer Science Center, Caltech/IPAC; Nikole Lewis, James Webb Space Telescope project scientist, Space Telescope Science Institute; and Michaël Gillon, principal investigator, TRAPPIST, University of Liege, Belgium.

The system has been revealed through observations from NASA’s Spitzer Space Telescope and the ground-based TRAPPIST (TRAnsiting Planets and PlanetesImals Small Telescope) telescope, as well as other ground-based observatories. The system was named for the TRAPPIST telescope.

NASA’s Jet Propulsion Laboratory, Pasadena, California, manages the Spitzer Space Telescope mission for NASA’s Science Mission Directorate, Washington. Science operations are conducted at the Spitzer Science Center at Caltech in Pasadena. Spacecraft operations are based at Lockheed Martin Space Systems Company, Littleton, Colorado. Data are archived at the Infrared Science Archive housed at Caltech/IPAC. Caltech manages JPL for NASA.

From Phys.org:

Temperate earth-sized worlds found in extraordinarily rich planetary system

February 22, 2017

Astronomers have found a system of seven Earth-sized planets just 40 light-years away. They were detected as they passed in front of their parent star, the dwarf star TRAPPIST-1. Three of them lie in the habitable zone and could harbour water, increasing the possibility that the system could play host to life. It has both the largest number of Earth-sized planets yet found and the largest number of worlds that could support liquid water.

Astronomers using the TRAPPIST-South telescope at ESO’s La Silla Observatory, the Very Large Telescope (VLT) at Paranal and the NASA Spitzer Space Telescope, as well as other telescopes around the world, have now confirmed the existence of at least seven small planets orbiting the cool red dwarf star TRAPPIST-1. All the planets, labelled TRAPPIST-1b, c, d, e, f, g and h in order of increasing distance from their parent star, have sizes similar to Earth.

Dips in the star’s light output caused by each of the seven planets passing in front of it (astronomy)—events known as transits—allowed the astronomers to infer information about their sizes, compositions and orbits. They found that at least the inner six planets are comparable in both size and temperature to the Earth.

Lead author Michaël Gillon of the STAR Institute at the University of Liège in Belgium is delighted by the findings: “This is an amazing planetary system—not only because we have found so many planets, but because they are all surprisingly similar in size to the Earth!”

With just 8% the mass of the Sun, TRAPPIST-1 is very small in stellar terms—only marginally bigger than the planet Jupiter—and though nearby in the constellation Aquarius (The Water Carrier), it appears very dim. Astronomers expected that such dwarf stars might host many Earth-sized planets in tight orbits, making them promising targets in the hunt for extraterrestrial life, but TRAPPIST-1 is the first such system to be found.

Co-author Amaury Triaud expands: “The energy output from dwarf stars like TRAPPIST-1 is much weaker than that of our Sun. Planets would need to be in far closer orbits than we see in the Solar System if there is to be surface water. Fortunately, it seems that this kind of compact configuration is just what we see around TRAPPIST-1!”

The team determined that all the planets in the system are similar in size to Earth and Venus in the Solar System, or slightly smaller. The density measurements suggest that at least the innermost six are probably rocky in composition.

The planetary orbits are not much larger than that of Jupiter’s Galilean moon system, and much smaller than the orbit of Mercury in the Solar System. However, TRAPPIST-1’s small size and low temperature mean that the energy input to its planets is similar to that received by the inner planets in our Solar System; TRAPPIST-1c, d and f receive similar amounts of energy to Venus, Earth and Mars, respectively.

All seven planets discovered in the system could potentially have liquid water on their surfaces, though their orbital distances make some of them more likely candidates than others. Climate models suggest the innermost planets, TRAPPIST-1b, c and d, are probably too hot to support liquid water, except maybe on a small fraction of their surfaces. The orbital distance of the system’s outermost planet, TRAPPIST-1h, is unconfirmed, though it is likely to be too distant and cold to harbour liquid water—assuming no alternative heating processes are occurring. TRAPPIST-1e, f, and g, however, represent the holy grail for planet-hunting astronomers, as they orbit in the star’s habitable zone.

These new discoveries make the TRAPPIST-1 system a very important target for future study. The NASA/ESA Hubble Space Telescope is already being used to search for atmospheres around the planets and team member Emmanuël Jehin is excited about the future possibilities: “With the upcoming generation of telescopes, such as ESO’s European Extremely Large Telescope and the NASA/ESA/CSA James Webb Space Telescope , we will soon be able to search for water and perhaps even evidence of life on these worlds.”

This research was presented in a paper entitled “Seven temperate terrestrial planets around the nearby ultracool dwarf star TRAPPIST-1″, by M. Gillon et al., to appear in the journal Nature.

Curaçao coral reefs video

Posted on February 22, 2017 by petrel41

This 1 February 2017 Dutch video is about biology student Auke-Florian Hiemstra, doing research about coral around Curaçao island.

Corals may get temporary reprieve from bleaching: here.

Afghanistan, endless war

Posted on February 22, 2017 by petrel41

This video says about itself:

22 February 2017

Tariq Ali reminds us of Afghanistan’s years of war, subsequent US and NATO occupation and the inter-ethnic division which these wars have caused. He introduces extracts from the documentary “From I through We to Community” which, with the support of AHRDO, sees young people addressing issues of ethnic discrimination head-on in order to find a way out of the ethnic tensions.

Relations between Afghanistan and Pakistan are fraught after a clash Friday over their disputed border killed at least twelve people and possibly many more, while forcing up to ten thousand villagers to flee for their lives: here.

New dragonfly species named after baby Bhutanese prince

Posted on February 22, 2017 by petrel41

Gyalsey emerald spreadwing dragonfly

This month, Naturalis Biodiversity Center in the Netherlands reports that a new dragonfly species from Bhutan has been named.

The insect was discovered in 2015, during a joint Bhutanese-Dutch expedition in eastern Bhutan.

Its name is Gyalsey emerald spreadwing dragonfly. Gyalsey means ‘prince’ in Bhutanese. The new species was named after the young crown prince of Bhutan; on his first birthday, the dragonfly’s name became known.

113 dragonfly species are known from Bhutan.

Dutch Naturalis biologists’ research in Bhutan: here.

United States Standing Rock pipeline struggle continues

Posted on February 22, 2017 by petrel41

This video says about itself:

22 February 2017

Mixed feelings towards the deadline for Standing Rock camps eviction. Trump’s executive order kick-started the pipeline construction, which will be complete in about 80 days. The Standing Rock struggle was historic. Hundreds of indigenous tribes fought back in a worldwide act of solidarity. Protesters faced police brutality and temperatures below zero. 700 water protectors were arrested. The struggle is not yet over.

São Tomé and Príncipe new wildlife discoveries

Posted on February 22, 2017 by petrel41

This 2014 video is about the wildlife of Príncipe island.

By BirdLife:

21 Feb 2017

Discovering the remarkable nature of São Tomé and Príncipe

There are undoubtedly discoveries to be made, with the invertebrate and marine biodiversity of the archipelago particularly understudied. Each new expedition to the islands uncovers species new to science.

By Merlin Veron, Synchronicity Earth

Synchronicity Earth is a UK charity which, on the basis of its research, aims to identify and increase support for high-priority conservation action globally.

On first inspection, the São Tomé Grosbeak Crithagra concolor might appear drab, unassuming, maybe even unremarkable. But first impressions can be deceiving. It is in fact one of the most endangered bird species on the planet, and was not sighted for over 100 years between 1890 and 1991, when it was rediscovered in the forests bordering Rio Xufexufe in the south-west of São Tomé.

Sightings of this finch since its rediscovery have been intermittent – the species was only photographed for the first time in 2006 and to date has still only been seen by a handful of non-Santomeans. BirdLife estimates a tiny extant population ranging from 50-250 individuals.

As well as its rarity, the taxonomy of this species is also fascinating and distinct. The São Tomé Grosbeak may be almost unique amongst bird species in that genetic studies suggest it evolved in sympatry with the Príncipe Seedeater Crithagra rufobrunnea, another endemic species.

Sympatric speciation occurs where two separate species evolve from a common ancestor without being geographically isolated from one another. This could happen if, for example, environmental conditions heavily favoured large individuals and small individuals, but not medium-sized ones, thus driving the evolution of two differently sized species.

The São Tomé Grosbeak is in fact the world’s largest canary with a ‘bullish’ head and powerful bill which rivals that of a Hawfinch – it dwarfs the Príncipe Seedeater and is almost twice its size, however questions still remain over what exactly drove the separation of these two species.

In fact if there is something unremarkable about the São Tomé Grosbeak it is that it inhabits an archipelago awash with other astonishing flora and fauna. The islands of São Tomé and Príncipe are located approximately 250km off the coast of Gabon, and as such have experienced somewhat of a ‘goldilocks effect’, in that they are close enough to the rich tropical forests of West and Central Africa to allow some populations to reach the islands, but distant enough so that once they do these populations become isolated and follow a distinct evolutionary trajectory.

Including the São Tomé Grosbeak there are a total of 28 endemic bird species on the islands, meaning a greater number of endemic species than the Galapagos Islands in an area approximately an eighth of the size. Amongst these species are the world’s largest Giant Sunbird Dreptes thomensis, Weaver Ploceus grandis and São Tomé Oriole Oriolus crassirostris, and its smallest Dwarf Ibis Bostrychia bocagei, a species which is also critically endangered and restricted to the primary forests of Obo Natural Park.

As well as endemic avifauna, the islands also harbour 1,230 described plant species, approximately 15% of which are endemic, as well as 19 butterfly species found only on this archipelago. The islands even hold 7 endemic amphibians, something which remains somewhat of a mystery considering amphibians’ known intolerance of salt water and the fact that as volcanic islands São Tomé and Príncipe were never connected to mainland Africa. There are also undoubtedly more discoveries to be made, with the invertebrate and marine biodiversity of the archipelago particularly understudied, with each new expedition to the islands uncovering species new to science.

The value of the biodiversity present on these islands has been recognised through a number of designations. Príncipe is recognised as a UNESCO Biosphere Reserve, both islands host KBAs and IBAs where primary habitats remain, the Tinhosas Islands which host more than 280,000 breeding seabirds are recognised as a Ramsar site, and the presence and critically endangered nature of the São Tomé Grosbeak, the Newton’s Fiscal Lanius newtoni, and the Dwarf Ibis triggered the recognition of Obo Natural Park as an Alliance for Zero Extinction site.

These designations all point to the importance of conserving this archipelago’s remarkable biodiversity, however historically habitat loss, in parallel with other threats, has driven many of the islands’ species towards extinction. Habitat destruction was rife during the Portuguese colonial era, with the islands first a centre for sugarcane production, and latterly coffee and cacao.

Whilst this led to widespread forest clearance, the primary, secondary and even shade forests on the islands continue to provide key habitats, but face new threats in the form of illegal logging, agro-industrial concessions and residential and commercial developments.

However, one particular threat which continues to hamper efforts to conserve biodiversity is a lack of local conservation capacity and community engagement. This is something which BirdLife has partnered with NGOs working in São Tomé and Príncipe to address, recognising that conservation begins with local people.

BirdLife has had a presence on São Tomé since 2006, with the conservation of the three critically endangered endemic bird species a key focus, culminating in the production of a species action plan produced in collaboration with the Santomean Government and local NGOs. One key pillar of BirdLife’s work has however focused on developing the capacity of civil society and raising awareness amongst the local population of the unique and threatened status of São Tomé’s biodiversity.

Studies have shown the low level of environmental education in São Tomé, particularly amongst rural populations. To try to instil an awareness and sense of pride in the biodiversity which the islands harbour BirdLife has worked with Portuguese partner SPEA (BirdLife Portugal) and the RSPB (BirdLife UK) to organise community meetings and collaborated with local artists to paint large murals of the critically endangered species in five villages.

Work is also underway in collaboration with Portuguese NGO Oikos to engage local musicians in producing a music and dance-based environmental awareness campaign celebrating São Tomé’s biodiversity and to engage with young people through a schools education programme and the establishment of nature clubs in the buffer region of Obo Natural Park.

The aim of these programmes is to increase awareness amongst the Santomean population about the importance of its biodiversity and the need for its conservation to protect livelihoods and environmental services. BirdLife hope to inspire future generations of conservation leaders on the island who can fill gaps in knowledge, identify key actions to protect species and ensure that the islands’ natural heritage is considered in decisions about its future development, meaning conservation is locally led.

Through engagement comes empowerment. This work is just one component of the activities needed to conserve São Tomé’s unique environment; and boosting local enforcement capacities, continuing to conduct scientific research to expand knowledge, and developing sustainable livelihood and development opportunities will also be integral.

However, where local people become engaged and invested in conservation, the future of enigmatic endemics such as the São Tomé Grosbeak will surely be more secure.

United States anti-Semitism, Stephen Bannon and Donald Trump

Posted on February 22, 2017 by petrel41

This video says about itself:

21 February 2017

Anti-semitism seems to be a growing problem lately… Ana Kasparian and Ben Mankiewicz, hosts of The Young Turks, discuss. Tell us what you think in the comment section below.

“As many as 200 headstones at a Jewish cemetery were toppled over the weekend here in a case that is making national headlines.

Anita Feigenbaum, executive director of the Chesed Shel Emeth Cemetery, said officials will be cataloging the damage Tuesday and notifying relatives whose families are affected. A monument company will decide which headstones need to be replaced and which need to be reset, she said.

Feigenbaum was emotional in describing the damage she saw.

“It’s hard to even express how terrible it was,” she said Tuesday morning. “It was horrible.”

Police are investigating the vandalism, which happened sometime over the weekend. No arrests had been made, as of Tuesday. Asked whether the incident is being investigated as a hate crime, Detective Lt. Fredrick Lemons II said police were keeping all options open….

Read more here.

By Niles Niemuth in the USA:

Mounting anti-Semitic attacks in US draw half-hearted response from Trump

22 February 2017

Some 200 headstones at a Jewish cemetery in University City, Missouri, in the suburbs of St. Louis, were damaged or overturned by vandals late Sunday or early Monday, in the most serious in a wave of anti-Semitic threats and actions this year.

Ultra-right and anti-Semitic forces have been encouraged by the inauguration of Donald Trump, and particularly his elevation of Stephen Bannon, the former CEO of Breitbart News, to a top position at the White House. Breitbart has been a leading promoter of the alt-right, the online designation of the rancid milieu of white supremacists, anti-Semites and neo-Nazis.

United States President Donald Trump, his adviser Steve Bannon, neonazis and the Ku Klux Klan, cartoon

No arrests have been made in the Missouri incident, and investigators have not yet formally determined that the attack was a hate crime rather than simple vandalism. But Karen Aroesty, St. Louis regional director of the Anti-Defamation League, told the press the Jewish community was alarmed. “Anxiety is high,” she said. “Your loved ones are there. Your memories are there.”

Both the Islamic Society of North America (ISNA) and the Missouri chapter of the Council on American-Islamic Relations denounced the vandalism. ISNA President Azhar Azeez released a statement saying, “We encourage our members to reach out to their local synagogue and Jewish neighbors to express their solidarity and support and to generously support the rebuilding of the recently desecrated cemetery.”

The FBI has opened an investigation into a series of bomb threats that have targeted several dozen Jewish Community Centers (JCCs) across the United States since the beginning of the year. Eleven centers were threatened via telephone on Monday including in Whitefish Bay, Wisconsin; St. Paul, Minnesota; Houston, Texas; Buffalo, New York; Albuquerque, New Mexico; and Birmingham, Alabama

So far, all of the threats at the facilities, which provide recreational, cultural and child care services to Jews and non-Jews alike, have turned out to be hoaxes. It is still unknown who is responsible for calling in the threats.

This week’s incidents followed phoned-in bomb threats on January 9, 18 and 31. So far this year, there have been 68 bomb threats at 53 JCCs in 26 states and at one center in Canada.

Paul Goldenberg, the director of the Secure Community Network, an agency that provides security services to Jewish institutions in North America, told the Jewish Telegraphic Agency that it appeared to be the same caller as in the previous threats.

The Jewish Telegraphic Agency released a recording at the end of last month of one of the threats that was made on January 18. In the recording, the caller chillingly threatens that a bomb is about to go off, killing a significant number of Jews.

“It’s a C-4 bomb with a lot of shrapnel, surrounded by a bag,” an electronically modulated voice states. “In a short time, a large number of Jews are going to be slaughtered. Their heads are going to be blown off from the shrapnel. There’s a lot of shrapnel. There’s going to be a bloodbath that’s going to take place in a short time. I think I told you enough. I must go.”

JCCs in the US have been targeted for attacks in recent years by anti-Semitic white supremacists.

In 1999, Buford O. Furrow, Jr., a member of the neo-Nazi Aryan Nations, injured three children, a teenage counselor and one staff member when he shot up the lobby of the North Valley JCC in the Los Angeles suburb of Granada Hills.

Neo-Nazi Frazier Glenn Miller killed three people and wounded two others in 2014 when he opened fire in the parking lot of the Kansas City JCC in the suburb of Overland Park.

The Trump administration has come under increasing pressure to respond to the wave of threats. Karen Aroesty of the Anti-Defamation League in St. Louis posed the question after the cemetery vandalism. “What is the government’s position relative to rising anti-Semitism and intolerance generally, and what will the government do to put a stop to it?” she said. “We’ve been asking that for several weeks now.”

After several weeks of silence from the White House about the bomb threats, Trump shut down two Jewish journalists at his news conference last Thursday when they tried to raise the question of the bomb threats and increasing incidents of anti-Semitic threats following his election.

“Some of that anger is caused by people on the other side,” Trump remarked to one of the reporters. “It will be by people on the other side to anger people like you.”

Finally on Tuesday, during a visit to the National Museum of African American History and Culture on Tuesday morning, Trump gave an interview to MSNBC in which he made obviously rehearsed remarks—but still poorly delivered and without genuine feeling—denouncing the recent anti-Semitic threats.

“The anti-Semitic threats targeting our Jewish community and community centers are horrible and are painful and a very sad reminder of the work that still must be done to root out hate and prejudice and evil,” Trump stated blithely.

Soon after Trump spoke, Stephen Goldstein, the executive director of the Anne Frank Center for Mutual Respect, released a statement denouncing the president’s remarks as a “Band-Aid on the cancer of Anti-Semitism that has infected his own Administration.”

“His statement today is a pathetic asterisk of condescension after weeks in which he and his staff have committed grotesque acts and omissions reflecting Anti-Semitism, yet day after day have refused to apologize and correct the public record,” Goldstein added. “Make no mistake: The Anti-Semitism coming out of this Administration is the worst we have ever seen from any Administration.”

Goldstein was referencing the White House’s official commemoration of Holocaust Remembrance Day last month in which it deliberately omitted any mention of Jews or anti-Semitism and instead lamented the “innocent people” killed by the Nazis during World War II. This move was seen as clear nod to the neo-Nazi alt.right, which seeks to empty the Holocaust of its significance and instead transform it into a general tragedy in which many people died.

Later in the day Tuesday, at a regular press conference, White House Press Secretary Sean Spicer was asked about the threats against Jewish community centers and skepticism over Trump’s latest remarks. He characterized Trump’s remarks Tuesday morning as “unbelievably forceful.” He was half right.

Responding specifically to the statement from the Anne Frank Center, Spicer complained, “It’s ironic that no matter how many times he talks about this, it’s never good enough.”

Despite being given the opportunity, none of the journalists in the briefing room raised the fact that Trump has staffed his White House with rabid anti-Semites, most notably Trump’s senior adviser and “chief strategist” Bannon, the former CEO of the far-right Breitbart News.

Bannon has brought with him a number of other White House staffers from Breitbart, a hotbed of white nationalism and anti-Semitism. People who were in daily contact with neo-Nazis six months ago are now in daily contact with the president of the United States.

MEET THE NEW KOCH FAMILY The reclusive Mercer father-daughter duo that helped propel Trump to the White House is responsible for the hiring of Steve Bannon. [HuffPost]

KUSHNER VS. BANNON The internal White House politics between President Donald Trump’s son-in-law Jared Kushner and top political adviser Steve Bannon reportedly culminated in Bannon’s removal from the National Security Council. [HuffPost]

‘TRUMP’S RIGHT-HAND TROLL’ Meet Stephen Miller, Trump’s speechwriter and “right-hand troll,” who is deploying the art of provocation from the White House. [The Atlantic]

Hawaii Rep. Beth Fukumoto (R) announced on Wednesday that she would be leaving the Republican Party and is seeking to join the Democratic Party instead. KITV 4 reports Fukumoto “cited racism and sexism as the core reasons why she’s leaving” during a press conference. Fukumoto was ousted by the Hawaii GOP from her position as House Minority Leader last month after she participated in the Women’s March. She said the party was “getting increasingly hostile to different opinions,” explaining she had previously been “booed for about 10 minutes straight for raising concerns about President Trump, then nominee Trump, and the way he treated women and minorities”: here.

Griffon vulture on video

Posted on February 22, 2017 by petrel41

This is a griffon vulture video. Made in the Netherlands, where these birds are rare.

I was privileged to see them in Aragon and in Extremadura in Spain.

‘Pro-human rights’ governments violating human rights

Posted on February 22, 2017 by petrel41

Photo by Jonathan Bachman/Reuters. A woman’s peaceful act of resistance during a protest in Baton Rouge, Louisiana, has become the symbol of a powerful moment in the Black Lives Matter movement

This June 2016 photo from Baton Rouge, Louisiana, USA is on the front page of the new Amnesty International annual report. It shows a Black Lives Matter demonstrator against police violence; who would be arrested.

Translated from Dutch NOS TV today, on Amnesty International‘s 2016/2017 report:

According to Amnesty director Shetty the French state of emergency is “deeply discriminatory” and more than 600 people, mostly Muslims, have been placed under house arrest. Also more than 140 demonstrations have been prohibited.

France in that is not unique, the organization says. Amnesty sees that more and more countries fiddle with the existing laws that protect human rights and fears a domino effect. “Countries that once had reputations as champions to defend human rights abroad, are now too busy curtailing the rights in their own countries, let alone to control others still.”

THERESA MAY’S “callous brutality” towards child refugees and the passing of “draconian legislation” has made Britain a “golden standard for human rights abuses,” Amnesty International warns in its annual report released today: here.

Howler monkeys’ eyes, new research

Posted on February 22, 2017 by petrel41

This video is called Howler Monkeys | National Geographic.

From Science News:

Howler monkeys may owe their color vision to leaf hue

Distinguishing red from green makes healthier leaves stand out

By Laurel Hamers

5:59pm, February 21, 2017

BOSTON — A taste for reddish young leaves might have pushed howler monkeys toward full-spectrum color vision. The ability to tell red from green could have helped howlers pick out the more nutritious, younger leaves, researchers reported February 19 at the annual meeting of the American Association for the Advancement of Science. That’s a skill their insect-eating close relatives probably didn’t need.

Primates show substantial variation in their color vision capabilities, both between and within species, said Amanda Melin, a biological anthropologist at the University of Calgary in Canada. Trichromatic vision (how most humans see) requires three light-sensitive proteins in the eye that can detect different wavelengths of light. Within most monkey species in Central and South America, only some individuals have trichromatic vision. Males have dichromatic vision — they’re red-green colorblind — and only some females can see the whole rainbow. Howlers are an exception — thanks to a duplicated gene on their X chromosomes, trichromatic vision is the norm for both males and females.

Howlers graze on leaves from Ficus trees and other plants when fruit can’t be found. In field observations of mantled howlers (Alouatta palliata) in Costa Rica, the monkeys preferentially munched on the younger, more nutritious leaves, Melin’s team found. The reddish hue of new leaves makes them pop more when seen with trichromatic vision than dichromatic vision, the researchers reported in a paper accepted for publication in Ecology and Evolution. Because young leaves are a fleeting treat and not a constant resource, monkeys able to spot them more quickly could have had a selective advantage.

Similar selection pressures might also help explain why Old World monkeys from Asia and Africa also have consistent trichromatic vision, Melin said. “What we might be seeing is a convergent evolution for animals who fall back on leaves when fruit isn’t around.”

On the other hand, other Central and South American monkeys usually go for insects, instead of leaves, when there’s no fruit. Dichromatic vision might be a better fit for their lifestyle, Melin said. “Color can impede ability to see patterns, borders and textures. Insects hide and camouflage.”

I was privileged to hear and see howler monkeys in Suriname and Costa Rica.

A new study analyzes the peculiar cranial structure and variability of the best-known species of South American howler monkey, Alouatta seniculus, using geometric models in three dimensions and multivariate statistics: here.